In order of preference, MLA recommends the use of a DOI, then a permalink, and lastly the URL. 

DOIs should include: https://doi.org/ in front of the DOI.

Permalinks are more stable URLs, often provided in the SPC databases.

URLs should not include the protocol http:// or  https://.

Long URLs, generally more than three lines, should be truncated. See the MLA style website for further details:

style.mla.org/urls-some-practical-advice/.

Works Cited

Author. “Article Title.” Journal Title, vol. #, no. #, Year, Page(s).

Opposing Viewpoints in Context, DOI or permalink or URL.

"Title of Article." Book Title, edited by Editor's First Name Last Name,

Publisher, Publication Date. Opposing Viewpoints in Context,

DOI or permalink or URL.

"Title of Article." Opposing Viewpoints Online Collection, Publication

Date. Opposing Viewpoints in Context, DOI or permalink

or URL.

Works Cited

"Gun Control." Opposing Viewpoints Online Collection,

2020. Opposing Viewpoints in Context, link.gale.

com/apps/doc/PC3010999212/OVIC?u=lincclin_

phcc&sid=bookmark-OVIC&xid=dbe92b08.

Peleg-Oren, et. al. "School-age Children of Fathers with

Substance Use Disorder: Are They a High Risk

Population?" Journal of Alcohol and Drug Education,

vol. 52, no. 2, 2008, pp. 9-30. Opposing Viewpoints

Resource Center, union.discover. flvc.org/permalink.

jsp?56105657026&ISSN=00901482

"Table: Alcohol Use Among Teens." Alcohol, edited by Scott

Barbour, Greenhaven Press, 2007. Opposing

Viewpoints in Context, link.gale.com/apps/doc/EJ

2210085036/OVIC?u=lincclin_spjc&sid=bookmark

-OVIC&xid=7f0549ae.

"A direct quote from the article" ("Gun Control"). According to Peleg-Oren et al.,"A direct quote from this article; however, only include the page number if the electronic article has the publication page numbers" (15).

or

Typically, a paraphrased sentence will have the author's name and the page number, if available, at the end. When paraphrasing from an article without a named author, use the title of the article for the citation and the page number when available ("Table: Alcohol Use Amongst Teens").